Foot-measuring method and device

ABSTRACT

The invention relates to a device that comprises: an element ( 1 ) for placement of a foot, which is provided with means ( 2 - 4, 7, 8 ) for positioning the foot ( 13 ) of a user and a mark ( 6 ) corresponding to a true measurement on the element ( 1 ); a camera ( 11 ) for capturing an image of the element ( 1 ) with the foot ( 13 ) placed in the required position; and a processor ( 12 ) for processing the image obtained in accordance with a conventional augmented reality program (AR), in order to obtain the true measurement of the length of the foot and to determine a size in accordance with conventional established sizes. The invention facilitates the purchase of footwear, both in a store and online.

OBJECT OF THE INVENTION

The present invention, as expressed in the wording of thisspecification, relates to a method and a device whose object is todetermine the measurement of the foot in order to obtain the appropriatefootwear size for the measured foot.

Another object of the invention is to allow an user to carry out themeasurement of the foot from a remote location, as it can be forinstance, from its own house, so as make remote shopping, like forinstance could be the case of buying from a catalogue and/or on theinternet.

BACKGROUND OF THE INVENTION

The disadvantages of the buying process of footwear in a physical shopare well known, given the need of trying on more than one footwear sizebefore finding the appropriate for the user. This same fact becomes atangible and significant handicap when buying on a virtual shop, bymeans of internet, given that in this case the user does not have thepossibility of trying on the footwear.

To promote the buys online of footwear, it is necessary to offer to theclient some security in the fact that the footwear that he/she is buyingsuits his/her foot.

In the state of the art, it is known the existing correlation betweenthe length of the foot and the size of the footwear in each of thedifferent shoe-size systems implemented in different countries (Europeansizes, British sizes, USA sizes). That is why, a device that allowsobtaining the length of the foot can provide by direct relation and bymeans of a table of equivalences, the shoe size number corresponding tothe foot of each user. A device of these characteristics facilitates theshopping in a physical store, given that it minimizes the time spenttrying on the footwear and it also may prove of invaluable helpespecially in the case of children, whose foot experiments a fast growthand because of their age they are less prone to provide precise dataabout the fit.

On this point it should be noted that in the state of the art, it isknown the use of augmented reality processes consisting in anapplication running in a processor so that on a true image a variableamount of additional information is added, generally by superimposition,in the form of virtual elements, which can be constituted by text,portions of bi-dimensional images, fix as well as in movement, ortridimensional objects. Thus, the image captured by a video camera istreated by the computer application, which enlarges it together with thevirtual objects and the information that comes with them, in order tosubsequently display said enlarged image on a screen, being the trueimage and the virtual elements associated to the same coordinate systemthat allows handling and displaying them together and in an integratedmanner.

In spite of the fact that there are numerous patented devices whereintheir ability to measure feet is specified, some of them, significantlyold, as it is the case for instance of the patent documents GB 191494614and U.S. Pat. No. 1,529,167, the truth is that none of them uses thesuperposition of a virtual element on a true image of a foot, by meansof the distinctive techniques of the augmented reality (AR), in order tofind out the foot measures.

In the state of the art, it is possible to find devices and/or methodsbased on the use of measuring apparatus having fix or movable physicalelements, as the ones described in the patent document GB 5901954 A, JP2008206916, WO 0200608896 or ES 250287Y. There are also devices based onsystems of light sensors, as the ones described in the patents WO200987618 or US 2007253004.

Other foot-measuring devices are based on the scanning of the foot intwo or three dimensions, as described in the patent document WO2004034832; on a three-dimensional reconstruction from bi-dimensionalimages, as described in the patent document GB 2417153, or US2006104503; on the measurement of photos with superposed or knownscales, as described in the patent document KR 20060109669; on paper orfoam printings, as described in the patent document WO 0135047; or onmathematical projections by using descriptive matrix, as described forinstance in the patent document GB 2352048.

Moreover, it should be highlighted that no relation between AR and themeasurement concept has been found, beyond vague references in themeasurement of geographical points of interest and the correlation ofthe measurements with true reference points, as described for instancein the patent document JP 2007156561; the evaluation of distances forthe correlation between true and virtual in reference and surgicalnavigation systems with AR, as described for instance in the patentdocument US 2005215879; or true-time measuring systems on referencedimages in the scope of the ophthalmic exam of the back of the eye, asdescribed for instance in the patent document US 5912720A.

Summarizing, the applicant does not have any knowledge about theexistence of a method and/or device that through the use of AR allowsmeasuring a foot and therefore to find out the according footwear sizenumber.

DESCRIPTION OF THE INVENTION

The invention provides a method and a device based on the use ofaugmented reality (AR), by means of which the length of the foot, andoptionally the width thereof or whatever other measures may be necessarycan be found out, by superimposing a movable virtual element onto a trueimage of the users foot positioned on a sole.

Thus, the invention provides a new foot-measuring method, whichcomprises a stage in which an element for the placement of a foot isobtained, which is provided with means for positioning the foot and amark, said mark corresponds to a true measurement on the sole, as forinstance can be the distance from the rear edge of the sole to the mark,and in such a way that said mark is provided in a position on theelement for the placement of the foot, wherein it is visible afterplacing the foot thereon, in the position required by the positioningmeans.

Next, an image of the element for the placement of a foot is obtained,with the foot placed in the required position and the obtained image ofthe element and the foot is processed in a processor, by means of aconventional procedure of augmented reality to superimpose at least onevirtual object on the mark of the processed image, displaying theobtained result, that is to say, the processed image in which thevirtual object is superimposed on the mark.

Thereafter, the procedure of the invention foresees obtaining thevirtual value of the true measurement in the processed image, in such away that when moving the virtual object up to the point in which thefront part of the foot ends, it allows calculating the distancetravelled according to the movement of the virtual object on saidprocessed image, and also allows obtaining the virtual length of thefoot in the image out from the distance travelled by the virtual objectand from the virtual value that has the true measurement determined inthe processed image, in such a way that after obtaining the virtuallength of the foot, this value is transformed into the true value of thefoot length, out from the true measurement included in the sole,determined by the mark, which is known by the processor.

To obtain the virtual length of the foot in the image, the verticalprojection of the heel of the foot corresponding to the rearmost pointof the foot is obtained, which is carried out using the means forpositioning the foot that are provided in the element for the placementof a foot. Next, a central line, longitudinal to the foot is traced anda line perpendicular to the longitudinal central line and tangent to thepoint where the front part of the foot ends is traced. Then, the virtualobject is placed in correspondence with this last line, in order toobtain the virtual length of the foot as described above.

Based on the measurement of the true length of the foot, the size ofsaid foot is obtained, accessing to a table of equivalences stored inthe processor, according to the sizes established in differentcountries, in such a way that the user knows his/her shoe-size in any ofthe systems adopted by each country.

In the preferred embodiment of the invention the element for theplacement of a foot is delimited by a sole, whose obtaining stage iscarried out by printing thereof on a sheet of paper, in which the meansfor positioning the foot are determined by cutting lines, folding linesand positioning lines, which enables after realizing the cut along saidcutting lines, and folding along the according folding lines, to obtaintwo wings joined together by an intermediate section, which are arrangedperpendicular to the sole surface, placing the wings according to theestablished positioning lines, and next said wings are pasted onto thesurface of the sole, so as a result the intermediate section and thewings establish a limit which constitutes the means for positioning thefoot. The intermediate section constitutes the means that allowsobtaining the vertical projection of the foot heel, to realize themeasurement of the virtual length in the obtained image. In thepreferred embodiment said intermediate section is located incorrespondence with the rear edge of the sole.

As it has been described, the foot size can be obtained after obtainingthe true measurement of the foot length, but additionally and accordingto the described procedure, the procedure of the invention also allowsobtaining the true value of the width of the foot, the length of thearch or any other required measurement, to obtain the foot size based onthese obtained measures, achieving a greater accuracy when obtaining thefoot size of the user and/or a more ergonomic footwear adapted to theconditions of the user's foot, having access to the according table ofequivalences, similarly to the procedure previously described wherebyonly the length of the foot was being measured.

Moreover, the invention relates to a device which allows executing thedifferent stages of the method described previously, to that end saiddevice comprises an element for the placement of a foot, which in thepreferred embodiment of the invention is delimited by a sole having thecharacteristics already described in the procedure of the invention. Itis foreseen that the element for the placement of a foot can be a sockprovided with a mark corresponding to a true measurement. Furthermore,the device comprises a camera for capturing images of the sole with thefoot placed in the required position by the means for positioning thefoot provided in the sole, in such a way that the image captured by thecamera is processed in a processor, in accordance with an augmentedreality program to carry out the measurements as described in the methodof the invention.

In an embodiment of the invention it is provided that the sole canincorporate printed silhouettes of feet with different sizes, tofacilitate the placement of the foot of the user.

Therefore, based on the disclosed description, the invention allowsobtaining the size of the foot of an user, in a fast, easy andeconomical way, and in such a way that it is considerably easier to buyfootwear in a physical store, by avoiding the user the need of trying ondifferent footwear and at the same time it promotes the purchase offootwear online.

Next, for better comprehension purposes of this specification, andmaking an integral part thereof, a series of figures are attached, inwhich by way of non limiting illustration the object of the inventionhas been represented

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1.—Shows in a schematic form a possible embodiment of the elementfor the placement of a foot, which is constituted by a sole that isobtained by printing it on a sheet of paper.

FIG. 2.—Shows a perspective view, equivalent to the previous figure,wherein the means for positioning the foot have been obtained aftermaking cuts and folds on the sheet of paper of the previous figure.

FIG. 3.—Shows a schematic representation of the device of the inventionand the stage of capturing the image of the foot of the user correctlyplaced on the sole.

FIG. 4.—Shows a schematic representation of an example of the true imagewith the virtual element used to measure the length of the foot, that isto say, it shows an augmented reality image as obtained by theprocessor.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Next, a description of the invention based on the aforementioned figuresis made.

In view of FIG. 1, it can be seen how the device of the inventionincludes an element 1 for the placement of a foot, which in theexemplary embodiment is constituted by a sole 1, printed on a sheet ofpaper, which is provided with cutting lines 2, folding lines 3 andpositioning lines 4, in such a way that by cutting along the lines 2 andfolding along the lines 3, two wings 8 are obtained, which are linkedtogether by an intermediate section 7, so the wings 8 are placed on thepositioning lines 4 and are fixed by means of an adhesive tape 9 ontothe surface of the sole 1, thus obtaining a sole with means forpositioning the foot 13 on which the heel has to be placed, in such away that its rear part abuts against the intermediate section 7 and thefoot sides against the wings 8.

Also, the sole 1 is provided with printed silhouettes 5 of feet withdifferent sizes to facilitate the placement of the foot 13.

Moreover, it should be highlighted that on the surface of the sole 1 amark 6 has been incorporated, which determines a true distance from therear part of the sole 1 to the position held by the mark 6 therein.

Furthermore, the device of the invention is provided with a camera 11for capturing images, which is connected to a processor 12 that includesa computer program of augmented reality, (AR). The processor isconstituted by a personal computer 12, and the camera 11 can be externalor be integrated in the personal computer 12 itself, as is the case withmany portable laptops from the state of the art.

Thus, based on the description made, it should be understood that oncethe sole has been obtained, according to what has been represented inFIG. 2, the foot 13 of an user can be positioned so the rear part of itsheel comes into contact with the intermediate section 7, and the sidesof said heel with the wings 8, and all that guided by the printedsilhouettes 5. In this position, in which the foot is correctly placed,as established by the positioning means, delimited by the wings 8 andthe intermediate section 7, an image of the sole 1 is obtained, with thefoot 2 placed in the required position, in such a way that the obtainedimage is processed by the personal computer 12 according to the computerprogram of augmented reality, through which one or more virtual elementsare added to the true captured image, and on the other hand the capturedimage is analyzed, while allowing to interact with the user anddetermining the foot measurements as described below.

When the processing of the obtained image of the sole and the foot isrealized through the procedure of augmented reality, a virtual object 14is superimposed on the mark 6, in such a way that it enables thecomputer program to establish the same coordinate and spatial locationsystem for the captured true image as for the virtual element 14 that issuperimposed onto the captured true image when executing the augmentedreality program. From that moment on the user can move back and forththe virtual element 14 by actuating the controls provided to that effectin the keyboard and/or mouse.

Moreover, the vertical projection of the foot heel corresponding to therearmost point of the foot is obtained, which is delimited by theintermediate section 7, and a central line, longitudinal to the foot istraced. Next, a line perpendicular to the central longitudinal line andtangent to the point where the front part of the foot 13 ends, istraced, and the virtual object 14 is moved until placing it visually incorrespondence with the line perpendicular to the central longitudinalline and tangent to the point where the front part of the foot (13)ends, which corresponds to the front position more distal of the foot ofthe user, that is to say, normally in correspondence with the frontextremity of the big toe thereof.

In this moment the computer program calculates the length from thevertical projection of the heel of the foot to the front part of thefoot, based on the ratio between both aforementioned coordinate systems,true and virtual, which is known and has been established beforehand.

To this end a priori the true distance from the rear part of the soleprinted on the paper to the position held by the mark 6 therein, isknown, as it has been described before. Also, the virtual distanceexisting between the rear part of the paper and the place where the mark6 is detected is known, in the internal units that are appropriate forthe computer program and that belong to the virtual coordinate system.From this data, the travel that takes place on said virtual coordinatesystem every time that a control on the keyboard or the mouse isactuated upon, is calculated.

Once this data is known, all there is to do is adding, when the travelis carried out towards the tip of the foot or subtracting, when thetravel is carried out towards the heel of the foot, the travel that theuser has caused on the virtual element 14 to calculate the final valueof the virtual length of the foot of the processed image.

From that moment on, by means of a simple rule of three thecorrespondence of said virtual length with regard to the true length ofthe foot 13 is established. If the virtual length from the limitdetermined by the intermediate section 7 to the mark 6 (LT_(V)) is equalto the true length of the limit 7 preceding the mark 6, then the truelength of the foot (LP_(r)) is equal to the virtual length of the foot(LP_(V)) multiplied by the true length from the limit behind the printedmark, the result being divided by the virtual length from the limit 7 tothe printed part 6, that is to say:

${LP}_{R} = \frac{{LP}_{V} \times {LT}_{R}}{{LT}_{V}}$

Therefore the true length of the foot 13 is obtained, whose value can berelated to a size of any of the footwear sizing systems used nowadays indifferent countries, by means of a table of equivalences of footlength/size that can be stored in the computer 12.

1. Foot-measuring method, characterized in that it comprises thefollowing stages: obtaining an element (1) for the placement of a foot(13) which is provided with means (2-4, 7, 8) for positioning the foot(13) and a mark (6), corresponding to a true measurement on the element(1), which is provided in a position in which it remains visible afterplacing the foot (13) on said element (1) in the position required bythe positioning means (7, 8); obtaining an image of the element (1) withthe foot (13) placed in the required position; processing the obtainedimage of the element (1) and foot (13) in a processor (12) by means of aconventional procedure of augmented reality (AR); for superimposing atleast one virtual object (14) on the mark (6) of the processed image,and displaying the processed image together with the virtual objective(14); obtaining the virtual value of the true measurement in theprocessed image; moving the virtual object (14) to the point where thefront part of the foot (13) ends; calculating the distance travelled bythe virtual object moved on the processed image; and obtaining thevirtual length of the foot (13) in the image based on the distancetravelled by the virtual object (14) and the virtual value of the truemeasurement in the processed image; transforming the virtual length ofthe foot obtained into the true length of the foot, based on the truemeasurement included in the element (1), known by the processor (12). 2.Foot-measuring method, according to claim 1, characterized in thatobtaining the virtual length of the foot (13) in the image based on thedistance travelled by the virtual object (14) and the virtual value ofthe true measurement in the processed image; it further comprisesobtaining the vertical projection of the heel of the foot, correspondingto the rearmost point of the foot, by the intermediary of the means (7)for positioning the foot; tracing a central line longitudinal to thefoot; tracing a line perpendicular to the central line longitudinal andtangent to the point where the front part of the foot (13) ends, andplacing the virtual object in correspondence with the line perpendicularto the longitudinal central line and tangent to the point where thefront part of the foot (13) ends.
 3. Foot-measuring method, according toclaim 1, characterized in that it comprises a stage for obtaining a sizeof the foot (13), based on the measurement of the true length of thefoot, obtained by accessing to a table of equivalences stored in theprocessor (12).
 4. Foot-measuring method, according to claim 1,characterized in that the stage for obtaining the element (1) comprisesthe printing of a sole (1) on a sheet of paper, wherein the means forpositioning the foot are determined by cutting lines (2), folding lines(3) and positioning lines (4), so after cutting and folding along theaccording cutting (2) and folding lines (3), two wings (8) are obtained,which are joined together by an intermediary section (7), perpendicularto the sole (1) surface, and then, positioning the wings (8) inaccordance with the positioning lines (4) in the indicated position andpasting them onto the surface of the sole (1), so the intermediatesection (7) and the wings (8) define a limit, which constitutes themeans for positioning the foot (13).
 5. Foot-measuring method, accordingto claim 1, characterized in that it comprises a stage for obtaining thetrue value of the measurement of one parameter of the foot (13) selectedfrom the width, arch length and a combination thereof; and a stage forobtaining a size of the foot based on the true measurement of the foot(13) length and the true measurement selected from among the width, thearch length and a combination thereof, accessing to a table ofequivalences stored in the processor (12).
 6. Foot-measuring device,characterized in that it comprises an element (1) for the placement of afoot (13), which is provided with means for positioning the foot of theuser and a mark (6), corresponding to a true measurement on the element(1), which is provided in a position such that it remains visible afterplacing the foot (13) on the element (1) in the position required by thepositioning means; a camera (11) for capturing an image of the element(1) with the foot (13) placed in the required position, an a processor(12) for processing the image of the element (1) and the foot (13)obtained, in accordance with a conventional augmented reality program(AR), in order to obtain the true measurement of a parameter of the footselected from length, width, arch length and a combination thereof. 7.Foot-measuring device, according to claim 6, characterized in that theelement (1) is constituted by a sole (1) in which the means forpositioning the foot of the user, are determined by a sheet (7)perpendicular to the surface of the sole (1) to define a limit for therear part of the heel of the foot (13), which constitutes the rearmostpoint of the foot (13).
 8. Foot-measuring device, according to claim 7,characterized in that the sheet perpendicular to the surface of the sole(1), comprises two wings (8) joined together by an intermediate section(7), in order to define a limit for the rear and lateral parts of theheel of the foot (13).
 8. Foot-measuring device, according to claim 6,characterized in that the sole (1) is provided with printed silhouettes(5) of a foot with different measures in order to facilitate the footpositioning (13).